It is email best practice to include a “view online” link at the top of marketing emails. See example attached.
Most CSM tools would host the email on the site/severs (similar to how images are typically hosted) and the link would be generated in a similar fashion to the “unsubscribe” link.
Gainsight support team have told me that this feature is currently not available.
I would strongly recommend that this feature is developed because by including a view online link, you can ensure that your email message is displayed as intended, regardless of the recipient's email client.
Thanks for your consideration.